Observational evidence for the Monin-Obukhov similarity under all stability conditions |
| |
Authors: | Shengjie Niu Lijuan Zhao Chunsong Lu Jun Yang Jing Wang Weiwei Wang |
| |
Institution: | Key Laboratory of Meteorological Disaster of Ministry of Education, School of Atmospheric Physics,
Nanjing University of Information Science and Technology, Nanjing 210044;Key Laboratory of Meteorological Disaster of Ministry of Education, School of Atmospheric Physics,
Nanjing University of Information Science and Technology, Nanjing 210044;Key Laboratory of Meteorological Disaster of Ministry of Education, School of Atmospheric Physics,
Nanjing University of Information Science and Technology, Nanjing 210044;Key Laboratory of Meteorological Disaster of Ministry of Education, School of Atmospheric Physics,
Nanjing University of Information Science and Technology, Nanjing 210044;Key Laboratory of Meteorological Disaster of Ministry of Education, School of Atmospheric Physics,
Nanjing University of Information Science and Technology, Nanjing 210044;Key Laboratory of Meteorological Disaster of Ministry of Education, School of Atmospheric Physics,
Nanjing University of Information Science and Technology, Nanjing 210044 |
| |
Abstract: | Data collected in the surface layer in a northern suburban area of Nanjing from 15 November to 29 December 2007 were analyzed
to examine the Monin-Obukhov similarity for describing the turbulent fluctuations of 3D winds under all stability conditions
and to obtain the turbulence characteristics under different weather conditions. The results show that the dimensionless standard
deviations of turbulent velocity components (σ
u
/u*, σ
υ
/u*, σ
w
/u*) and dimensionless turbulent kinetic energy (TKE) can be well described by “1/3” power law relationships under stable, neutral,
and unstable conditions, with σ
u
/u* > σ
υ
/u* > σ
w
/u*. Land use and land cover changes mainly impact dimensionless standard deviations of horizontal component fluctuations, but
they have very little on those of the vertical component. The dimensionless standard deviations of wind components and dimensionless
TKE are remarkably affected by different weather conditions; the deviations of horizontal wind component and dimensionless
TKE present fog day > clear sky > overcast > cloudy; the trend of the vertical wind component is the reverse. The surface
drag coefficient at a Nanjing suburban measurement site during the observation period was obviously higher than at other reported
plains and plateau areas, and was approximately one order larger in magnitude than the reported plains areas. Dimensionless
standard deviation of temperature declined with increasing |z′/L| with an approximate “?1/3” slope in unstable stratification and “?2/3” slope in stable stratification. |
| |
Keywords: | Monin-Obukhov similarity theory boundary stability boundary layer parameterizatio |
本文献已被 CNKI SpringerLink 等数据库收录! |
| 点击此处可从《大气科学进展》浏览原始摘要信息 |
| 点击此处可从《大气科学进展》下载免费的PDF全文 |
|